In order to get Handheld Contact set up to only sync selected groups from ACT! you need to complete the following:

1. Have the groups created in ACT!.  If they are not created, please see this LINK for more info.
2. Open Handheld Contact on the PC/server.
3. Click on Contacts Info on the left.
4. Choose Change.
5. Click on Advanced button.
6. Select button that states 'Excluded CLEARED activities'.
7. Select date range for activities and set 'starting from' far into the future (at least a few years).
8. Choose OK.
9. Select the custom groups that were created from Step 1.
10. You cannot unselect the 'Auto-Sync-HHC' group, so ignore that box.
11. When finished, press OK.
12. Finally, you need to RESEND ALL DATA.

Please see this link as well: http://support.handheldcontact.com/Knowledgebase/Article/View/19/0/what-is-the-auto-sync-hhc-group-in-act-and-how-does-it-work